Hi All -
Finally time for a new post! (Something I’m surprised I haven’t covered yet).
This post will inform you on how to run Magento code outside of Magento. All you need is to have access to Magento’s ‘app/Mage.php‘ file.

This will be handy code for a few things:

• Integration with 3rd party items – shared sessions, or just shared themes
• Ajax calls – although not the preferred solutions for Ajax calls, it is a quick and easy one

To expand on these ideas a bit more:
Integration:
-You can use this code to output HTML that is outputted in Magento anywhere. You might want to integrate Wordpress and steal the navigation from Magento, for instance. You might want to share sessions and users between your CMS and Magento (and even share the databases). This can help you get started on doing that.

Ajax:
-Because you can use this code to output any block/template, you can use it for Ajax calls in your Magento build. You build your block and template (and any other needed objects) as usual and output them via this code.

Here is a sample:

<?php
require_once 'app/Mage.php';
umask(0);
/* not Mage::run(); */
Mage::app('default');

// get layout object
$layout = Mage::getSingleton('core/layout');

//get block object
$block = $layout->createBlock('catalog/product_ajax');

/* choose whatever category ID you want */
$block->setCategoryId(3);
$block->setTemplate('catalog/product/ajaxevents.phtml');

echo $block->renderView();

?>

We can see in this block of code that we are grabbing the custom block ‘catalog/product_ajax‘.
This is simply a block that grabs a product collection. In this case, we are able to set the category id to 3. (See the post on custom blocks to help you get a feel for what this might look like).

This block is then setting the .phtml template to ‘ajaxevents.phtml‘ and rendering the view. You hopefully can see how this would be useful for Ajax calls.

Other code that might help you along your way:
From php architect’s book (might be outdated!!! We haven’t tested this particular code):

include('app/Mage.php');
Mage::App('base'); //might be "default"

$customer = Mage::getModel('customer/customer');
$customer->loadByEmail('some@email.address'); /* need a users email address */
$session = Mage::getSingleton('customer/session');
$session->start();

Here is some session code that will grab cart information. Notice that this code doesn’t start a session:

<?php

$mageFilename = 'app/Mage.php';
require_once $mageFilename;

umask(0);
Mage::app();

/* Magento uses different sessions for 'frontend' and 'adminhtml' */
Mage::getSingleton('core/session', array('name'=>'frontend'));

// $cart = Mage::getSingleton('checkout/cart')->getItemsCount();
// $cart = Mage::helper('checkout/cart')->getItemsCount();

$cart = Mage::helper('checkout/cart')->getCart()->getItemsCount();

echo 'cart items count: ' . $cart;

?>

Yet another block of code with some interested stuff:

require_once 'app/Mage.php';
umask(0);

$app = Mage::app('default');

/* Init User Session */
$session = Mage::getSingleton('customer/session', array('name'=>'frontend'));

if ($session->isLoggedIn()) {
/* do something if logged in */
} else {
/* do something else if not logged in */
}

By Fido from exploremagento.com

Related posts:

1. Add Adwords tracking code to order confirmation page in Magento
2. Move mini-cart in the sidebar to the header (or anywhere) in Magento
3. Custom checkout cart – How to send email after successful checkout
4. Making use of Magento getSingleton method
5. Some custom Blocks to help you show products